 The theory of these spaces is represented in many works, see e.g. [1]}, [2]},
[3]}, [4]}, [5]}, [6]}, [7]}, [8]}, [9]},
[10]}, [11]}, [12]}, [13]},[14]},
[15]}, [16]}, [17]}, [18]}, [19]}, [16]}, [21]} etc. As a rule
it was considered the case of finite measure:  \( \ \mu (X) = 1. \ \)  The case \( \ \mu (X) =\infty \ \)  and the operators acting in these spaces was covered in
particular in [22]}, [23]} - [24]}, [25]} - [26]}.
